Tendon Systems for Robots

ABSTRACT

A method of assembling a portion of a robot, including, providing a robot arm having an exterior surface and providing a tendon retaining element, having a first half having a first major surface, defining open channels and a second half having a second major surface. Then, placing a tendon in each of the open channels of the first half and placing the second major surface on the first major surface, thereby creating a set of closed channels each having a tendon passing therethrough and creating a finished tendon retaining element. Finally, attaching the finished tendon retaining element about the exterior surface of the robot arm, so that the tendons extend along the length of the robot arm.

RELATED APPLICATIONS

This application is a continuation of application U.S. Ser. No.14/734,390, filed on Jun. 9, 2015, which is incorporated by reference asif fully set forth herein.

BACKGROUND

Robotics is gradually shifting from the design of robots that move veryquickly through a carefully defined set of motions to robots that have ahigher intelligence and a greater range of operation. As roboticsadvances, various barriers to further progress may emerge. Among theproblems encountered in robot design is the use of complex mechanisms totransfer force from a motor to an arm or finger that needs to be moved.These complex mechanisms may include discrete fasteners and multiplehinge components, that are challenging to align and secure. This adds tothe expense and defect rate of the manufacturing process.

Also, the greater the mechanical complexity, the greater the tendencyfor a mechanism to break down and require repair. The task of repair isalso made more difficult, as complexity is increased. A simpler systemof interconnections for force transfer would ease the task oforiginating a robust robot design.

SUMMARY

The following embodiments and aspects thereof are described andillustrated in conjunction with systems, tools and methods which aremeant to be exemplary and illustrative, not limiting in scope. Invarious embodiments, one or more of the above-described problems havebeen reduced or eliminated, while other embodiments are directed toother improvements.

In a first, separate aspect, the present invention may take the form ofa robot tendon system having a robot arm having an exterior surface, andfurther rigid elements, each of which is moveably attached to the robotarm or to another of the further rigid elements. Further, a tendonretaining element defines a set of closed channels, and has a majorexterior surface that is attached to the major surface of the robot arm.Finally, tendons extend through the closed channels and are attached tothe rigid elements.

In a second, separate aspect, the present invention may take the form ofa method of assembling a portion of a robot, including, providing arobot arm having an exterior surface and providing a tendon retainingelement, having a first half having a first major surface, defining openchannels and a second half having a second major surface. Then, placinga tendon in each of the open channels of the first half and placing thesecond major surface on the first major surface, thereby creating a setof closed channels each having a tendon passing therethrough andcreating a finished tendon retaining element. Finally, attaching thefinished tendon retaining element about the exterior surface of therobot arm, so that the tendons extend along the length of the robot arm.

In a third separate aspect, the present invention may take the form of atendon and rigid element assembly that includes a tendon subassembly,including a tendon having a longitudinal end having a mating portion.Also, a rigid element has a mating portion. Further, a first one of themating portions includes a set of projections and a second one of themating portions defines a set of indentations that are sized and shapedto accept and retain the projections and wherein the set of projectionsare secured in the set of indentations, thereby securing the tendon tothe rigid element.

In a fourth separate aspect, the present invention may take the form ofa tendon and rigid element assembly, comprising a tendon subassembly,including a tendon having a longitudinal end having a pair of wings,extending laterally from the longitudinal end of the tendon and a rigidelement having a mating portion. The wings are secured about the rigidelement to secure the tendon subassembly to the rigid element.

In addition to the exemplary aspects and embodiments described above,further aspects and embodiments will become apparent by reference to thedrawings and by study of the following detailed descriptions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of a first side of a set of robot tendonassemblies.

FIG. 2 is an isometric view of the set of robot tendon assemblies ofFIG. 1, taken from a second side, that is opposed to the first side.

FIG. 3 is an isometric view of the set of robot tendon assemblies ofFIG. 1, taken from the first side, and also showing two halves of atendon sleeve, with the tendons being placed in a first half of thesleeve.

FIG. 4 is an isometric view of the tendon assemblies and sleeve halvesof FIG. 3, with the sleeve halves being closed about the tendons, toform a complete sleeve.

FIG. 5 is a top view of a robot hand showing the tendon assemblies andsleeve of FIG. 4, placed into their environments, and with the tendonassemblies attached to the rigid elements of the hand.

FIG. 6 is an expanded detail section view, taken along lines 6-6 of FIG.5.

Exemplary embodiments are illustrated in referenced drawings. It isintended that the embodiments and figures disclosed herein are to beconsidered illustrative rather than restrictive.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1 and 2, a set of tendons 10 are shown, in this casefor manipulating the fingers of a robot hand. Each tendon 10 is made upof a tension transmitting portion 12, each defining a lumen 13, and anattachment portion 14. Referring to FIG. 2, each attachment portion 14is, on a first major surface, made up of a central field of deformableprojections 16 and a pair of wings 18, covered with loop material 20. Ona second major surface, facing opposite from the first major surface,attachment portion 14 is covered with hook material 22. Accordingly,when an attachment portion 14 is wrapped about a post, hook material 22mates with loop material 20. In an alternative preferred embodiment (notshown), wings that are generally similar in shape to wings 18 each havean adhesive surface for adhesively bonding said wings about a post.

Referring to FIGS. 3 and 4, an upper sleeve-half 30 and a lowersleeve-half 32 are joined together about tendons 10, to form a retainingsleeve 34 for tendons 10. The interior surfaces of sleeve 34 thatcontact tendons 10 are either made of a naturally lubricious material,such as poly tetrafluoroethylene or coated with a lubricant. Channelsare formed by protruding linear elements 36, which interlock with narrowchannels 38.

Referring to FIG. 5, a robotic hand assembly 40 is shown, in formmimicking a human hand having carpals 42, metacarpals 44, proximalphalanges 46, intermediate phalanges 48 and distal phalanges 50. Thethumb does not have an intermediate phalange 48. In the embodimentshown, a first tendon 10 is attached to the back or dorsal side of eachintermediate phalange 48, in part by wings 18. In the case of the thumb,a tendon 10 is attached to the proximal phalange. In like manner, asecond tendon 10 is attached to the front or palmar side of eachintermediate phalange 48, and on the proximal phalange 46 of the thumb.In FIG. 5, only the attachment portion 14 is visible of the secondtendons that attach to the intermediate phalanges.

In an alternative preferred embodiment, the tendons 10 are each attachedto a distal phalange 50. In an alternative embodiment, there is aseparate tendon 10 attached to each phalange, 46, 48 and 50, or a singletendon attached to each phalange, 46, 48 and 50 that form into a singlefinger. In one preferred embodiment tendons 10 are moved by a tensionforce applicator (not shown), to pull the intermediate phalanges 48inwardly. In this embodiment, tendons 10 are slidingly engaged withbones 42, 44 and 46, with guide elements keeping them in place. Inanother embodiment, intermediate 48 or distal phalange 50 is pulled bymeans of a tendon (not shown) that is threaded through lumen 13. Ineither one of these embodiments, lumens 13 may be used for conductiveelements, carrying electrical signals.

Referring to FIG. 6, which is a detail view of an attachment betweentendon 10 and intermediate phalange 48, projections 16 fit into matchingreceptacles 52, to collectively form a strong bond between tendon 10 andphalange 48. Although in the embodiment shown the bones 42 mimic theshape of human finger bones, in alternative preferred embodiments theyare simply a set of shafts, moveably attached together. More broadly,phalanges 46, 48 and 50 may be considered rigid elements. The scope ofthis invention is not limited to robot assemblies that have a similarappearance to the bone structure of a human hand, but extends to alljointed assemblies.

While a number of exemplary aspects and embodiments have been discussedabove, those possessed of skill in the art will recognize certainmodifications, permutations, additions and sub-combinations thereof. Itis therefore intended that the following appended claims and claimshereafter introduced are interpreted to include all such modifications,permutations, additions and sub-combinations as are within their truespirit and scope.

1. A method of assembling a portion of a robot, comprising: (a)providing a robot arm having an exterior surface; (b) providing a tendonretaining element, having a first half having a first major surface,defining open channels and a second half having a second major surface;(c) placing a tendon in each of said open channels of said first half;and (d) placing said second major surface on said first major surface,thereby creating a set of closed channels each having a tendon passingtherethrough and creating a finished tendon retaining element; and (e)attaching said finished tendon retaining element about said exteriorsurface of said robot arm, so that said tendons extend along the lengthof said robot arm.
 2. The method of claim 1, wherein said first majorsurface is lubricious.
 3. The method of claim 1, wherein said secondmajor surface is lubricious.
 4. The method of claim 1, wherein saidfirst surface and said second surface define interlocking elements andwherein said act of placing said second major surface on said firstmajor surface further includes locking together said interlockingelements, thereby joining said second major surface to said first majorsurface.
 5. The method of claim 4, wherein said interlocking elementsare linear and extend in the direction of said open channels at theexterior of said tendon retaining element, thereby sealing said tendonretaining element at its sides after said second surface is joined tosaid first surface.
 6. The method of claim 4, wherein said interlockingelements are linear and extend along either side of each open channel,thereby sealing each channel along its sides, after said second surfaceis joined onto said first surface.
 7. The method of claim 4, furtherincluding at least partially filling at least some of said open channelswith lubricant prior to sealing each channel along its sides.
 8. Themethod of claim 1, further wherein a set of fingers are each moveablyattached to said robot arms and further including the step of attachingeach tendon to a finger.